This article explores the potential of involving smallholder farmers in hybrid development for their low-external input farming systems. We have developed a conceptual model of the procedures, based on five assumptions: (a) the hybrids are bred for adaptation to local needs and preferences; (b) the dependence on and need for genetic diversity is taken into account; (c) breeders collaborate closely with farmers also in the initial stages of the breeding programme, that is, in establishing the breeding goals by identifying the desired traits and preferred local populations as (one of the) crossing parents; (d) hybrid seed production can be integrated into the farmers’ local seed system; and (e) farmers and breeders can agree on intellectual property rights, access and benefit sharing in a fair and transparent way. We illustrate the procedural consequences of these assumptions with reference to the case of a participatory maize breeding programme in southwest China, from 2000 to 2012, that included both open-pollinated and hybrid maize improvement. We show how farmers’ early involvement in hybrid development during the pre-breeding stage, including broadening the base populations with farmer-maintained local landraces, can support co-evolution of the genetic resources in farmers’ fields.